Since its introduction by R. A. Fisher, the design of experiments has played an important role in agricultural and scientific studies. Genichi Taguchi has recently renewed the interest of product and process engineers in design of experiments techniques.
Design of experiments is the first step in a process to evaluate how factors influence response variables. An experiment design may be defined as a data collection sheet which specifies how the values of the input factors of the experiment are to be set for each trial of the experiment. This data collection sheet is an essential ingredient for accurate, efficient experimentation. To produce an efficient experiment design the statistician makes use of a statistical analysis software package, such as for example, SAS available from SAS Institute. They may then go further and evaluate this design by hand, a long and tedious process even with the use of a computer.
Currently expert systems are available for designing experiments but are limited to selection from a limited class of designs. See for example, "An expert system for experimental design in off-line quality control" by Lee, Phadke, and Keny in Expert Systems, November, 1989, Vol. 6, No. 4 page 238. Prior to this invention there were no other means available for automatically generating and analyzing the power of balanced experimental designs. Rather than forcing the user to accept one of a predetermined set of experiment designs, the expert system of the present invention generates a design meeting the user's requirements and evaluates that design.